Dramatic changes are occurring in the wireless, switching and networking industries which are creating a need to transmit information at an ever-increasing rate. For instance, Internet content is expected to be received by cell phones, notebook computers and the like without the need for wires and with considerable speed. In many applications, the challenge is to increase data rates between circuit boards and cables. As the speed and frequency of these devices increase, all of the components within a system must be capable of performing at those speeds. This, in turn, creates challenges with respect to “noise” and interference between the devices. Therefore, it is necessary to isolate or shield the signals from each other by placing an electrical shield between the signals. Heretofore, many electrical connectors have used terminal arrays which have signal terminals alternating with significantly sized shielding or ground terminals along the entire length of the terminal array. Of course, this approach significantly increases the sizes of the electrical connectors in high speed applications where miniaturization is a constant goal.
Electrical connectors often are mounted on printed circuit boards where the “real estate” on the boards is a premium. A “mezzanine” connector assembly provides electrical interconnection between parallel circuit boards. Mezzanine boards are frequently used where more function is needed than will fit on the primary board. Mezzanine boards also facilitate system partitioning necessary to offer multiple options and expandability. The connector assembly must be capable of operating at the same high data rates as the primary and mezzanine boards. The signals in such arrangements or systems must be electrically shielded or isolated so that the connector assembly has very low cross-talk between the signal lines.
Frequently, high speed mezzanine connectors must transmit differential pair signals, requiring that two signals or terminals are spaced within one cavity so that they are electrically coupled to significantly reduce the common mode noise and to electrically shield or isolate these differential pairs from each other.
The present invention is directed to solving these various problems and providing a simple and very efficient and effective shielding system in electrical connectors, such as connectors which are mounted on printed circuit boards.